I have many problems with Sam Harris, even as I largely agree with him. He is also pretty funny in a low key way. Here is is discussing why Mormonism is necessarily even more ridiculous than Christianity.
However, his argument, while funny, is wrong. Not that it matters. Maybe I’ll discuss it later.
For Sam Harris to pick on Mormonism in particular is disingenuous. To any rational person, ANY religion or or belief system is going to appear ridiculous, and at the same time, inherently evil – much like circus clowns. Is one belief more stupid than another? Is one religion true and the others wrong? The answer to both is, obviously, no. Like the Tooth Fairy, Santa, and the chocolate egg-laying Easter Bunny, Christianity is a belief that is introduced to children (because they will believe ANYTHING). These children then grow up and introduce the fantasy to their own children, thus fostering many long held passive-aggressive traditions.
Mormonism is an unsophisticated twist on a traditional bit of make-believe. I think that’s the primary difference between Mormonism and Scientology: one was the brainchild of a nutball with a limited and childlike imagination, the other the mind droppings of a successful science fiction writer. Mormonism appealed to an ignorant populace who were blown away with ideas that, in the early 19th century, "just made sense". Scientology on the other hand has a rugged PR department and a large pool of dimwitted celebrity fish to lure in. Today both religions are the crutches of fools and the tools of scoundrels.
What makes religion appealing (and truly insidious) are those little bits that do make sense and, if practiced responsibly, would actually make the world a better place. The sad thing is that every one of those behaviors are a natural part of a healthy, well-adjusted life. No commandments necessary.